In 1999, a scientist wanted to look at some data from soil samples collected on Mars in 1975 by the Viking lander. He wanted to test a theory about detecting the existence of Martian bacteria and microbes–in other words, finding life on Mars. The scientist thought he would find what he needed on a NASA website somewhere, but it wasn’t that easy. The original data had been misplaced, and when the huge magnetic tapes that stored the data were found, they were “in a format so old that the programmers who knew it had died.” Someone finally found a ream of paper printouts propping a door open and humanity’s understanding of the universe expanded a bit more. The tragic sense that would have accompanied the loss of this knowledge is echoed in accounts of the destruction of the Library at Alexandria, and probably why book-burnings are seen as a sure sign that a society is unhealthy